Dental chair



(NoModelJ A, W. BROWNE. DENTAL CHAIR.

I N0. 520,947. Patented June 5, 1894.

WITNESSE 1 I INVENTOR @fir m A v 9W r A- '1 wAsmua ARTHUR W. BROWNE, OF'PRINOES BAY, NEW YORK, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA PENNSYLVANIA.

\DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 520,947, dated June 5, 1894.

' Application filed December 27,1893. Serial No. 494,848. (No model.)

To all whom it may concern:

Be it known that I, ARTHUR W. BROWNE, a citizen of the United States, residing at Princes Bay, in the county ofRichmond and State of New York, have invented certain new and useful Improvements in Dental Chairs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain improvements, as hereinafter claimed, in means for imparting a wide range of vertical adjustment to the bodies of dental chairs which are adapted to be horizontally turned and vertically tilted, as well asfraised and lowered.

In my application for United States Letters Patent, Serial No. 494,803, filed December 26, 1893, are shown improvements of the class to which my present invention relates, and I make no claim herein to features claimed-or claimable in my said prior application.

The accompanying drawing shows my improvements in side elevation, parts in section, a portion only of the chair-body being represented.

My improvements are represented as applied to the wellknown chair shown in United States Letters Patent No. 197,441, dated No-' vember 20, 1877, and No. 483,807, dated October 4, 1892. As in said patents there is provided a support (hereinafter termed the main elevating and lowering support) for the chair body A, said support consisting of the plunger A having vertically adjustable connection with the base or pedestal A and actuated by means of the jointed elevating lever A? and co-operating devices, the lever being jointed to the cylinder B which is adapted to turn horizontally in the pedestal and to be locked therein by the locking lever B The vertically adjustablesupport has'no horizontal or turning movement in the cylinder B to which the lifting lever is attached, and'the manner of upholding andof lowering the support is as fully explained in the abovementioned Patent No. 197,441.

The chairbody is carried by supplementary elevating and lowering mechanism interposed 7 ing support A, so as to increase the range of vertical adjustment of the chair-body, and this supplementary raising and lowering mechanism is constructed and supported as follows:

The main elevating and lowering support is provided at its upper end with a suitably attached bracket 0 rigid therewith and provided at its outer end with a supporter D projecting downwardly therefrom parallel with the main elevating and lowering support and serving to carry and guide a vertically adjustable bar or rod E having the gear rack or row of teeth 6. A pinion F gears with this gear rack, and a clamp screwactuated by a lever G serves to lock the adjustable rod against movement in its supporter. At its upper end the adjustable rod is provided with the chair-body carrier H of the supplementary raising and lowering mechanism, the chair body being jointed to its carrier at g over the main raising and lowering support, so as to be capable of tilting. A detent segment H adapted to be adj ustably engaged with a projection h of the chair-body carrier serves to hold the chair-body in the position to which it may be adjusted by tilting about its jointed connection with the supplementary elevating and lowering mechanism. A cam-like arm or eccentric sheave segment I attached to the pinion F or to its shaft has connection with one end of a coiled spring J at its point or end t'most remote from the pinion shaft eccentrically to which the periphery of the sheave segment is arranged. The opposite or lower end of the spring has connection with a lug on the supporter D of the rod E of the supplementary elevating and lowering mechanism. The spring acts, it will be seen, to approximately counterbalance the weight of the chair-body, as its tendency is to rotate the pinion and lift the adjustable rod with which the pinion meshes. It will further be seen that the construction of the sheave segment is such that as the pinion is rotated during elevation of the rack rod and the spring becomes weaker by its contraction, its leverage on the pinion increases thus compensating to a greater or less extent, according to how much movement is imparted to the pinion, for the loss of strength of the spring.

PATENT OFFICE. .v

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From the above description it will be understood that the chair-body, when the chair is unoccupied, may readily and quickly be raised or lowered by hand, and that when the supplementary elevating and lowering mechanism is clamped against independent vertical movement this mechanism and consequently the chair-body and its occupant may be raised or lowered with the main elevating and lowering support, for final adj ustment.

In some instances a crank may be applied to the pinion shaft to assist in the vertical adjustment of the rack rod.

I claim as my invention- 1. The combination of the pedestal or base, the main elevating and lowering support carried thereby, the bracket rigid with the upper end of the main support and provided with the downwardly projecting supporter parallel with said support, the rod vertically adjustable in said supporter and sustained at all times in an upright position parallel with the main support, means for securing the vertically adjustable rod against movement in the supporter, the chair body carrier at the upper end of said rod, the chair body having jointed connection with said carrier to tilt upon it, and means for securing the chair body in its tilted position upon its carrier, substantially as set forth.

2. The combination of the pedestal or base, the main elevating and lowering support carried thereby, the bracket rigid with the upper end of the support and provided with the downwardly projecting supporter extending parallel with said support, the vertically adj ustable rod sustained by said supporter and provided with the gear rack, the chair-body carrier at the upper end of said rod, the chairbody having jointed supporting connection with said carrier, the pinion meshing with the gear rack of the adjustable rod and the counterbalancing spring having connection at its opposite ends with said supporter and pinion, substantially as set forth.

3. The combination of the pedestal or base, the main elevating and lowering support car ried thereby, the supporter having supporting connection with said main support and extending parallel therewith, the vertically adj ustable rod sustained by said supporter and provided with the gear rack, the chair-body having supporting connection with the upper end of said rack rod, the pinion meshing with the rack of the adjustable rod, the eccentric sheave segment connected with the pinion, and the counterbalancing spring connected with said segment and the supporter of the rack rod, substantially as set forth.

In testimony whereof Iaiiix my signature in presence of two witnesses.

ARTHUR W. BROWNE.

\Vitnesses:

GEO. D. HEcK, GRANT CARPENTER. 

